"Hey, kid. Wanna make it in Hollywood? Well, first we have to cover you in fake blood and have you run around while being chased by a crazy, masked killer. And then, if your acting is up to snuff, maybe we won't have you killed off within the first 20 minutes of the movie."

That's how we imagine most of these 29 celebs first got their careers going when they decided they wanted to be famous actors. It's not an usual choice to start out in horror; those movies are cheap to make and people with barely (or zero) acting credits can get cast as long as they can scream, look pretty and don't mind sometimes appearing half-naked.